This invention relates to solid compositions wherein a functional group is entrapped in the lattice of a cross-linked hydrophobic polymer during in situ polymerization of the monomers forming the polymer lattice. More particularly, the invention relates to comb-like polymers which have entrapped various chemicals and provide for their sustained release.
The art is replete with attempts to render functional materials amenable to release on demand through encapsulation. Encapsulation confines materials in discrete units or capsules as the result of coating particles of the material with an encapsulant. The coating wall or encapsulating material used in encapsulation includes natural or synthetic polymers which permit release of the functional material by fracture, degradation or diffusion.
Handbook of U.S. Colorants for Food, Drugs and Cosmetics by Daniel M. Marmion, A. Wile. Interscience Publication, Second Edition, 1984, which is herewith incorporated by reference, discloses food flavorants and pigments which could be utilized in the present invention.
In Pesticides: Preparation and Mode of Action by R. Cremlyn, John Wiley and Sons Publication, 1978, and Pesticides Guide: Registration, Classification and Applications by J. Keller and Associates, Inc., Neenah Wisconsin, Section 167.3, 1984 which are herein incorporated by reference, disclose the various pesticides, and insect attractants which may be utilized in connection with the invention.
Styrene-divinylbenzene copolymer, which is one crosslinked polymer that is useful in the practice of the present invention, can be prepared as described in U.S. Pat. No. 4,291,980 of Patterson or the article of Patterson entitled "Preparation of Cross-Linked Polystyrenes and Their Derivatives for Use as Solid Supports or Insoluble Reagents" in Biochemical Aspects of Reaction on Solid Supports, Stark, ed. Academy Press, pp. 189-213, 1971.
It is an object of the present invention to provide a novel form of entrapment of the functional material which does not encapsulate the functional material.
This invention provides a unique combination of polymers and functional materials, which results in compositions wherein the functional materials rather than being encapsulated by coating materials are dispensed throughout and entrapped within a hydrophobic polymeric lattice. These compositions are useful for incorporating a variety of functional materials into a variety of products such as cosmetic and non-cosmetic products. Furthermore, the amount of functional materials which can be entrapped in the lattice are much higher than heretofore achievable by encapsulation.